Please enjoy this free sample of our premium content featuring Jim Cramer. To get all of Cramer's premium content free for a limited time, please register here.NEW YORK ( RealMoney) -- We used to call it "building a thesis." That means you take enough data from enough places and you put it all together and link it to the prospects of individual companies. Here's what I am seeing. This morning, we got a terrific note from Frank Mitsch, my favorite chemical analyst, talking about chemicals prices coming down, notably for classic building block propylene. For Mitsch, that means cutting numbers for LyondellBasell Industries ( LYB). For me it means that the raw costs of so many products are at last showing the weakness that could lead to margin expansion -- not contraction -- for consumers of the polys and the ethyls, the basics of plastics.